McWill Game Gear Full Mod Kit

Many years after McWill released the first modern screen mod for the Game Gear, he has come back with an updated design that finally allows for integer scaling that utilizes the full size of the screen.  Known as the McWill Ver 4.0 or simply “640×480”, this modification is available as both a traditional screen mod for the original hardware, or a “Full Mod” which allows you to replace all of the old PCBs with a modern design.

(Both are available at in the US)

The Full Mod requires you to use the original ASICs, CPU and cartridge slot from the Game Gear, so your games are still technically running on original hardware, albeit the least amount of original hardware possible.

The “Full Mod” utilizes a daughter board to house the original ASICs, CPU and clock crystal. The kit comes with a 1-ASIC and a 2-ASIC board. When populated the board sockets in to the motherboard.

There are something like half a dozen Game Gear screen mods available, but up until this point all of them employed screens that did not allow for a proper integer-scale of the Game Gear’s original 160×144 resolution. This meant that the original pixels were scaled unevenly to make everything fit, resulting in warps and waves during horizontal scrolling.  For many people the additional screen brightness and clarity provided by these mods made the compromise acceptable, but for others, this was a difficult thing to get past.  With this new screen mod (or full mod) that’s no longer a compromise you have to make.

I’ve written about the “Full Mod” in more detail, including some installation advice and additional images on my blog here:

The Full Mod has a lot of cool features:

  • Works with 1-ASIC or 2-ASIC (hardware for both is included)
  • Footprint for Genesis/SMS controller ports for using external controllers (the 2nd player slot is functionally identical to the original link port)
  • Customizable RGB LEDs next to each of the buttons and the D pad.
  • A built-in analog control stick (optional)
  • Built-in HDMI output socket (640×480 resolution)
  • New sound and power boards
  • Built in support for rechargeable LiPo batteries, and USB-C charging
  • Functional brightness wheel

It’s not all roses, though as there are a number of downsides

  • Requires case modification – the top center screw post must be removed for the new screen to fit inside the GG case. (Other case modification is recommended if not strictly required – for using the analog joystick, for better fitment of the batteries, and for proper viewing area for the new screen)
  • LiPo batteries are required (USB power is for charging only, and can’t power the unit)
  • The “correct” LiPo batteries are not simple to find at the moment. (Any 3.7V battery can be used, but not all fit optimally or offer reasonable play time between charges).
  • The screen is slightly wider than the original. The original screen frame needs to be widened for you to be able to see the whole thing.
  • It’s not cheap. When you factor in the Full Mod, the batteries, the donor board, tax and shipping, you’re at or over the cost of an Analogue Pocket + Adapter.
  • The HDMI output (on mine anyway) suffers from horrible jailbars.
  • The HDMI output won’t work on many TVs due to the archaic VGA resolution.
  • The audio board still has a noticeable hum that gets worse with brighter screen elements.
The McWill 640×480 screen is slightly wider than the original leading to the right side of the image being obscured unless the case opening is widened. This is worse for some games than others.


This is, by far the best Game Gear replacement screen option available which still uses original Sega hardware (even if the only original hardware it uses are the ASICs, CPU and cartridge slot) simply by virtue of finally offering integer scaling and thus smooth scrolling. It also comes with a number of premium features for people who really want to go all the way and trick out their Game Gear with custom cases and internal LEDs.  The fact that there are no electrolytic capacitors in the new design mean that’s one less thing that will fail over time.

Unfortunately the Full Mod is far from perfect. The requirement to use difficult-to-source batteries instead of just being able to power it off of a USB-C power supply is a major drawback in my book, as is the fact that there is no reliable method for correctly re-sizing the frame to fit the new screen width. The noisy audio and HDMI output were also disappointments considering this kit has all freshly engineered PCBs which I expected would have accounted for and eliminated these issues in the design.

Finally, the kit is not cheap, clocking in at just under $200 US before tax and shipping. By the time you factor in the price of shipping, tax, batteries and a donor Game Gear you’re in the neighborhood of $300 US in materials alone. If you want to use a fresh case with new buttons and a glass lens, you’re definitely over the $300 mark.  This means it might be more cost effective to just buy an Analogue Pocket and a Game Gear adapter.  But the real question is: is it worth it?  If running on original hardware and integer scaling is important to you, then some version of this screen mod is definitely worth it.
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